Fluid pressure actuated grippers are widely employed and typically take the form of a pneumatic or hydraulic differential motor whose cylinder is fixedly mounted to a transfer device. At the forward or rod end of the cylinder housing, a gripper jaw mounting structure is fixedly mounted on the cylinder to pivotally support a pair of opposed gripper jaws which are coupled to the piston rod of the motor by a linkage. This arrangement allows movement of the piston in one direction so that the jaws are pivoted to an open position, and upon movement of the piston in the opposite direction the jaws are driven to a closed workpiece gripping position. In typical operation, the gripper jaws close upon a workpiece grasping same, and advance to position the workpiece in some operative relationship with a work station or portion of a production line. The gripper then opens to release the workpiece and retracts from the work station or production line while the work operation or task is performed. At the conclusion of the operation or task, the gripper advances back into the work station and the jaws again close upon the workpiece and carry it away from the work station.
Such fluid pressure actuated grippers are generally designed for use with particular workpieces to be transferred and with specific work stations or production lines. For example, some workpieces and/or work stations may require wider or narrower gripper jaws, different types of gripper jaws, gripper jaws that open at different angles, jaws that require different clearance requirements, etc., to complete a particular task. Furthermore, such grippers carry workpieces which may be of a variety of sizes or thicknesses.
A known problem associated with production lines employing numerous grippers, each of which are completing a specific task as part of a sophisticated series of operations, is that if one gripper fails to complete its task, it could create multiple failures along the production line. This failure has the potential of stopping the entire production line, thus, delaying completion of the operation, as well as the possibility of delaying other dependent operations.
A common type of failure is the gripper failing to grip the workpiece. Typically, the workpiece falls out of the gripper while it is being carried. Another common failure is the gripper carrying more than one workpiece at a time (commonly termed double sheeting). Consequently, these failures can damage equipment which translates into increased costs and potential losses in both time and revenue. It would, therefore, be beneficial to provide an article sensing assembly for use with fluid actuated grippers. It would be further beneficial to provide an article sensing assembly that can be adjustable for use with various gripping arrangements.
Accordingly, an illustrative embodiment of the present disclosure provides a fluid actuated parts gripper assembly comprising, a pair of opposable pivoting jaw members, a fluid driven actuator, a linkage structure, a sensor target, a mounting and a sensor. The linkage structure is driven by the fluid driven actuator and is coupled to at least one of the pair of opposable jaw members. In addition, the fluid driven actuator causes the linkage structure to move at least one of the pair of opposable jaw members. The sensor target is coupled to the linkage structure and is movable therewith. The mounting is located adjacent the sensor target. The sensor is mounted on the mounting configured to detect the sensor target.
Other illustrative embodiments may comprise the mounting being adjustable relative to the sensor target; the sensor being fixed relative to the mounting; the mounting being configured to receive the sensor target such that the sensor target is moveable within the mounting; the mounting including a slot within which the sensor target is moveable; the mounting comprising at least one slot configured to receive a fastener that selectively fixes the mounting to the gripper; the at least one slot is a pair of slots; an adjustment member coupled to the mounting for incrementally adjusting the location of the mounting relative to at least one of the pair of jaw members; the adjustment number being an adjustable spacer comprising a body having a plurality of sides, each of the plurality of sides located at a different length from a central location on the body; the central location of the adjustable spacer being a bore disposed there through; the adjustable spacer having opposed surfaces, each being non-equidistant from the location; the adjustable spacer being a hexagonal body with opposed surfaces each being non-equidistant from the location; the at least one of the opposed surfaces of the adjustable spacer being positionable adjacent an abutment located on the mounting to selectively reposition the mounting relative to the gripper assembly; the member is a pivot body that pivots about an axis of rotation and is engagable with a portion of the mounting a distance spaced apart from the axis of rotation; an engagement member attached to the pivot body being engagable to a corresponding receiver in the mounting to secure the mounting to the gripper assembly a determined position; the engagement member being engagable with a plurality of receivers in the mountings.
Additional features and advantages of the gripper assembly will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the gripper assembly as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the article sensor assembly, and such exemplification is not to be construed as limiting the scope of the article sensor assembly in any manner.